Interspinous process implant

ABSTRACT

A system and method for providing a spinal implant having a main body, a proximal anchor, a distal anchor, and an internal plunger. The proximal anchor comprises a nut having an internal bore. The distal anchor comprises a plurality of wings having a first closed configuration and a second open configuration. The internal plunger is housed within a central bore of the main body. The distal end of the internal plunger is operatively connected to the first wing and the second wing to selectively move the wings between the first closed configuration and the second open configuration, and vice versa.

RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 17/389,418 filed Jul. 30, 2021, which is a continuation of U.S.patent application Ser. No. 16/998,171, filed Aug. 20, 2020, thedisclosures of which are incorporated herein by reference.

BACKGROUND 1. Field

Embodiments of the invention relate to spinal implants. Morespecifically, embodiments of the invention relate to a percutaneously orposteriorly introduced spinous process implant and fusion device.

2. Related Art

The spine consists of a column of twenty-four vertebrae that extend fromthe skull to the hips. Discs of soft tissue are disposed betweenadjacent vertebrae. In addition, the spine encloses and protects thespinal cord, defining a bony channel around the spinal cord, called thespinal canal. There is normally a space between the spinal cord and theborders of the spinal canal so that the spinal cord and the nervesassociated therewith are not pinched.

Over time, the ligaments and bone that surround the spinal canal canthicken and harden, resulting in a narrowing of the spinal canal andcompression of the spinal cord or nerve roots. This condition is calledspinal stenosis, which results in pain and numbness in the back andlegs, weakness and/or a loss of balance. These symptoms often increaseafter walking or standing for a period of time.

There are a number of non-surgical treatments for spinal stenosis. Theseinclude non-steroidal anti-inflammatory drugs to reduce the swelling andpain, and corticosteroid injections to reduce swelling and treat acutepain. While some patients may experience relief from symptoms of spinalstenosis with such treatments, many do not, and thus turn to surgicaltreatment. The most common surgical procedure for treating spinalstenosis is decompressive laminectomy, which involves removal of partsof the vertebrae. The goal of the procedure is to relieve pressure onthe spinal cord and nerves by increasing the area of the spinal canal.

Interspinous process decompression (IPD) is a less invasive surgicalprocedure for treating spinal stenosis. With IPD surgery, there is noremoval of bone or soft tissue. Instead, an implant or spacer device ispositioned behind the spinal cord or nerves and between the interspinousprocesses that protrude from the vertebrae in the lower back.

Examples of a particularly useful interspinous process implant andfusion devices are disclosed in commonly assigned U.S. Pat. Nos.9,861,399, 8,945,184; 9,314,276, 9,907,581, and 9,757,164, thedisclosures of which are all incorporated herein by reference in theirentirety.

The invention provides an improvement over prior interspinous implantdevices by constructing an implant that is substantially shorter inlength than prior devices. This will advantageously reduce the overallsize and profile of the device, thereby making implantation safer andeasier.

The construction of the implant according to an embodiment of theinvention also allows for easier removal of the device afterimplantation, if desired. The ability of the surgeon to both selectivelyopen and close the wings of the device is another advantage over priordevices. Because the wings can be closed after implantation, the implantof the invention can be removed by the same small lateral incisionthrough which it was originally inserted. Removal of prior devicesgenerally requires an additional posterior incision to manually closethe wings before the device can be extracted.

Additionally, the device of the invention does not require a removableend piece. This improves the safety and ease of the procedure byreducing the number of steps in the implantation process. Fewerseparable parts of the implant also reduces cost and simplifiesmanufacturing.

SUMMARY

Embodiments of the invention solve the above-mentioned problems byproviding a system and method for minimally invasive spinal fusion.

A first embodiment of the invention is directed to a spinal implantcomprising: a main body, a proximal anchor, a distal anchor, and aninternal plunger. The main body has an outer surface, a central boretherein, a proximal end, a distal end, and a longitudinal axis extendingtherebetween. The proximal anchor comprises a nut having a proximalside, a distal side, and an internal bore. The distal anchor comprises aplurality of wings having a first closed configuration and a second openconfiguration, wherein the plurality of wings comprises a first wing anda second wing. The internal plunger has a proximal end, a distal end,and is housed within the central bore of the main body. The distal endof the internal plunger is operatively connected to the first wing andthe second wing to selectively move the plurality of wings between thefirst closed configuration and the second open configuration.

A further embodiment of the invention is directed to a spinal implantcomprising a main body, a proximal anchor, a distal anchor, and alinkage assembly. The main body has an outer surface, a central boretherein, a proximal end, a distal end, and a longitudinal axis extendingtherebetween. The main body includes external threads on at a least aportion of the outer surface. The proximal anchor comprises a nut havinga proximal side, a distal side, and an internal bore having internalthreads. The distal anchor comprises a first wing and a second wingconfigured to be selectively opened and closed. The linkage assemblyconnects the first wing and the second wing to the main body.

Another embodiment of the invention is directed to a method of placing aspinal implant at a treatment site comprising: providing a spinalimplant in a first closed configuration; placing the spinal implant in apatient at a desired treatment site; and sliding the internal plungerdistally along the longitudinal axis to move the plurality of wings tothe second open configuration. The method may further comprise slidingthe internal plunger proximally along the longitudinal axis to move theplurality of wings to the first closed configuration to withdraw thespinal implant from the patient.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Other aspectsand advantages of the invention will be apparent from the followingdetailed description of the embodiments and the accompanying drawingfigures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Embodiments of the invention are described in detail below withreference to the attached drawing figures, wherein:

FIG. 1 is a perspective view of a first embodiment of the implant of theinvention in an open configuration;

FIG. 2 is a cross-sectional view of the first embodiment of the implantof the invention in an open configuration;

FIG. 3 is a perspective view of an embodiment of the main body of theinvention;

FIG. 4 is a perspective view of the first embodiment of the implant ofthe invention in the closed configuration;

FIG. 5 is a perspective view of an embodiment of a plunger of theinvention;

FIG. 6A is a perspective view of an embodiment of a first linkage of theinvention;

FIG. 6B is a perspective view of an embodiment of a second linkage ofthe invention;

FIG. 7 is another perspective view of the first embodiment of theimplant of the invention in an open configuration;

FIG. 8 is a cross-sectional view of the first embodiment of the implantof the invention in the open configuration;

FIG. 9A is a side perspective view of a first embodiment of a first wingof the invention;

FIG. 9B is a bottom perspective view of the first embodiment of thefirst wing of the invention;

FIG. 9C is a top view of the first embodiment of the first wing of theinvention;

FIG. 10A is a side perspective view of a first embodiment of a secondwing of the invention;

FIG. 10B is a bottom perspective view of the first embodiment of thesecond wing of the invention;

FIG. 10C is a top view of the first embodiment of the second wing of theinvention;

FIG. 11 is a perspective view of a bolt of the invention;

FIG. 12 is a perspective view of a removable head for the bolt of theinvention;

FIG. 13 is a perspective view of an embodiment of a nut of theinvention;

FIG. 14 is a cross-sectional view of the first embodiment of the implantof the invention in the closed configuration;

FIG. 15 is another cross-sectional view of the first embodiment of theimplant of the invention in the closed configuration;

FIG. 16 is a view of the first embodiment of the implant of theinvention implanted in the spine of a patient;

FIG. 17 is a perspective view of a second embodiment of the implant ofthe invention in an open configuration;

FIG. 18 is a cross-sectional view of the second embodiment of theimplant of the invention in an open configuration;

FIG. 19 is a perspective view of a second embodiment of a plunger of theinvention;

FIG. 20 is a perspective view of a second embodiment of a first linkageof the invention;

FIG. 21A is a top perspective view of a second embodiment of a firstwing of the invention;

FIG. 21B is a bottom perspective view of the second embodiment of afirst wing of the invention;

FIG. 21C is a side perspective view of the second embodiment of a firstwing of the invention;

FIG. 22 is a perspective internal view of the second embodiment of thefirst and second wings, the first and second linkages, and the plungerof the invention, with the main body hidden;

FIG. 23 is a perspective view of the second embodiment of the implant ofthe invention in a closed configuration;

FIG. 24A is a side perspective view of a second embodiment of a nut ofthe invention;

FIG. 24B is a bottom perspective view of the second embodiment of a nutof the invention;

FIG. 24C is a bottom end view of the second embodiment of a nut of theinvention; and

FIG. 25 is a view of the second embodiment of the implant of theinvention implanted in the spine of a patient.

The drawing figures do not limit the invention to the specificembodiments disclosed and described herein. The drawings are notnecessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the invention.

DETAILED DESCRIPTION

The following detailed description references the accompanying drawingsthat illustrate specific embodiments in which the invention can bepracticed. The embodiments are intended to describe aspects of theinvention in sufficient detail to enable those skilled in the art topractice the invention. Other embodiments can be utilized and changescan be made without departing from the scope of the invention. Thefollowing detailed description is, therefore, not to be taken in alimiting sense. The scope of the invention is defined only by theappended claims, along with the full scope of equivalents to which suchclaims are entitled.

In this description, references to “one embodiment,” “an embodiment,” or“embodiments” mean that the feature or features being referred to areincluded in at least one embodiment of the technology. Separatereferences to “one embodiment,” “an embodiment,” or “embodiments” inthis description do not necessarily refer to the same embodiment and arealso not mutually exclusive unless so stated and/or except as will bereadily apparent to those skilled in the art from the description. Forexample, a feature, structure, act, etc. described in one embodiment mayalso be included in other embodiments, but is not necessarily included.Thus, the technology can include a variety of combinations and/orintegrations of the embodiments described herein.

Embodiments of the invention are directed to a minimally invasiveinterspinous-interlaminar fusion device for the temporary fixation ofthe thoracic, lumbar, and sacral spine while waiting for bony fusion tooccur. The implant can be attached to the posterior non-cervical spineat the spinous processes to provide immobilization and stabilization ofthe spinal segments. A threaded main body of the implant providescontrolled distraction.

One embodiment of the invention is shown in FIG. 1, which illustrates aninterspinous process implant 100 in an open configuration. Implant 100may include a main body 112 having a distal end 114 and a proximal end116. Implant 100 further includes a nut 200 on the proximal end 116 ofmain body 112 and extendable first and second wings 300 a, 300 b on thedistal end 114 of main body 112. As can be seen in the cross-sectionalview of FIG. 2, implant 100 further includes a plunger 400 and first andsecond linkages 500 a, 500 b for operatively connecting first and secondwings 300 a, 300 b to main body 112, as will be described herein.

FIG. 3 illustrates an embodiment of main body 112. Distal end 114includes a conical distal tip 118 having a rounded distalmost end. Insome embodiments, the conical distal tip has a sharp pointed distalmostend. In some embodiments, main body 112 includes helical threads 120 onan exterior surface thereof. In some embodiments, main body 112 mayalternatively or additionally include cutting threads or box threads.Helical threads 120 may be provided along the entire exterior surface ofmain body 112 or along only a portion of the exterior surface of mainbody 112. In some embodiments, the threads may have a depth of about 0.5to about 3.0 mm, an angle of about 45° to about 100°, and a spacing ofabout 1.0 mm to about 4.0 mm. In some embodiment, the threads may have adepth of about 1.0 mm, an angle of about 60°, and a spacing of about1.75 mm. In some embodiments, distal tip 118 has a smooth exteriorsurface without any threads thereon. In some embodiments, the distal tip118 is a solid tip for providing strength during insertion of theimplant 100.

Main body 112 further includes a proximal portion 122 extending from theproximal end 116, having hollow bore 124. The majority of hollow bore124 may be substantially cylindrical. Proximal end of hollow bore 124may have a particular shape such as a hexagonal perimeter configured toreceive an insertion tool therein (not shown). Proximal end of hollowbore 124 may also include detents 125 adapted for receiving and lockinga distal end of an insertion tool therein (not shown).

Main body 112 also includes a distal portion 126 extending from thedistal end 114, having a substantially rectangular window 128. Thewindow 128 extends from a first lateral side 130 to a second lateralside 132, a top flat interior wall 134, and a bottom flat interior wall136. At the distal end of the window 128, top wall 134 includes anopening 138 a therethrough and bottom wall 136 includes an opening 138 btherethrough. Openings 138 a, 138 b are configured to receive a bolt 700for mounting wings 300 a, 300 b, as seen in FIG. 4.

FIGS. 4 and 15 illustrate implant 100 with wings 300 a, 300 b in aclosed configuration. Window 128 of main body 112 is configured to housea distal portion of the plunger 400, first and second linkages 500 a,500 b, and first and second wings 300 a, 300 b when in the closedconfiguration.

FIG. 5 illustrates an embodiment of plunger 400. Plunger 400 has adistal end 402 and proximal end 404. Proximal end 404 is configured tobe located within the bore 124 of main body 112 and distal end 402 isconfigured to be located within the window 128 of the main body 112, asseen in FIG. 2. Plunger 400 can be moved longitudinally within the bore124 and window 128 to open and close the wings 300 a, 300 b, as will bedescribed further below.

With respect to FIG. 5, proximal end of plunger 400 has a central bore406 for receiving an inserter device (not shown) therein. In someembodiments, central bore 406 of plunger 400 may be threaded tocooperate with threading on an inserter device. Plunger 400 has asubstantially Y-shaped construction, having a first arm 408 a and asecond arm 408 b extending from a solid central portion 410. First arm408 a and second arm 408 b have a space 409 therebetween. Centralportion 410 has two opposed curved indentations 412 a, 412 b on an outerside, as can be seen in FIG. 5. First arm 408 a and second arm 408 beach have a hole 414 a, 414 b extending therethrough for receiving amounting pin 600 therein. In order to connect wings 300 a, 300 b to theplunger 400, linkages 500 a, 500 b are mounted within the space 409between the arms 408 a, 408 b. In some embodiments, plunger 400 may havea total length of about 13 mm to about 15 mm. In some embodiments,plunger 400 may have a total length of about 13.9 mm. First and secondarms 408 a, 408 b may have a length of about 4-5 mm. First and secondarms 408 a, 408 b may have a length of about 4.5 mm.

In an alternative embodiment, a plunger may have two heads having aT-shape or dove-tail feature that rides in a mating grove on theunderside of wings 300 a, 300 b. In a further alternative embodiment, aplunger may be connected by an umbrella-like feature having linkagesthat ride within a groove on an underside of the wings 300 a, 300 b.

FIGS. 6A and 6B illustrate an embodiment of first and second linkages500 a, 500 b, respectively. First linkage 500 a has a first end 502 aand a second end 504 a. In some embodiments, first linkage 500 a issubstantially oval shaped with first end 502 a having a rounded edge 506a, and second end 504 a having a rounded edge 508 a. First linkage 500 afurther includes a straight top edge 510 a and an indented curved bottomedge 512 a. First end 502 a includes a hole 514 a extending therethroughand second end 504 a includes a hole 516 a extending therethrough. Holes514 a and 516 a are each configured to receive a mounting pin 600therein. First linkage 500 a includes a substantially planar top surface518 a and a substantially planar bottom surface 520 a.

As can be seen in FIG. 6B, second linkage 500 b is substantiallyidentical to first linkage 500 a. Second linkage 500 b has a first end502 b and a second end 504 b. In some embodiments, second linkage 500 bis substantially oval shaped with first end 502 b having a rounded edge506 b, and second end 504 b having a rounded edge 508 b. Second linkage500 b further includes a straight top edge 510 b and an indented curvedbottom edge 512 b. First end 502 b includes a hole 514 b extendingtherethrough and second end 504 b includes a hole 516 b extendingtherethrough. Holes 514 b and 516 b are each configured to receive amounting pin 600 therein. Second linkage 500 b includes a substantiallyplanar top surface 518 b and a substantially planar bottom surface 520b. In some embodiments, first and second linkages 500 a, 500 b may havea length of about 8 mm to 10 mm. In some embodiments, first and secondlinkages 500 a, 500 b may have a length of about 9.2 mm. The distancebetween the holes 514 a and 516 a (and 514 b and 516 b) may be about 5mm to about 7 mm. The distance between the holes 514 a and 516 a (and514 b and 516 b) may be about 5.9 mm. Curved bottom edges 512 a, 512 bmay have a curvature with a radius of about 3.5 mm.

FIG. 7 shows a perspective view of implant 100 in an open configuration,with wing 300 a shown in front. As can be seen in FIG. 7, first linkage500 a and second linkage 500 b are mounted within the space 409 betweenarms 408 a, 408 b of plunger 400.

FIG. 8 illustrates a cross-sectional view of implant 100 in an openconfiguration. As can be seen in FIG. 8, second end 504 a of firstlinkage 500 a is connected to first end 502 b of second linkage 500 b.Planar bottom surface 520 a of first linkage 500 a is placed in contactwith planar top surface 518 b of second linkage 500 b. As can be seen inFIGS. 2 and 8, a mounting pin 600 is inserted through hole 516 a insecond end 504 a of first linkage 500 a, hole 514 b in first end 502 bof second linkage 500 b, hole 414 a in first arm 408 a of plunger 400,and hole 414 b in second arm 408 b of plunger 400 to allow for rotationof the linkages 500 a, 500 b thereabout. The opposite ends of linkages500 a, 500 b are connected to the wings 300 a, 300 b to allow forrotation thereof, as will be described further below.

FIGS. 9A, 9B, and 9C show perspective views of an embodiment of firstwing 300 a. Wing 300 a has a distal end 302 a, a proximal end 304 a, afirst lateral side 306 a, and a second lateral side 308 a. In someembodiments, distal end 302 a includes at least one fang extendingtherefrom adapted for engaging bone and/or tissue. In other embodiments,a bottom surface of wing 300 a may include a flat roughened surface toachieve gripping of the bone and/or tissue.

In some embodiments, distal end 302 a includes first and second fangs310 a, 311 a having a gap 312 a therebetween. In some embodiments, thedimension of the gap 312 a may be about 1.5 mm to about 6 mm. In someembodiments, the gap 312 a may be about 3 mm. In some embodiments, firstfang 310 a has a sharp pointed tip 314 a and second fang 311 a has asharp pointed tip 313 a. First fang 310 a is provided on first lateralside 306 a and is connected to first extension 316 a. Second fang 311 ais provided on second lateral side 308 a and is connected to secondextension 318 a. First extension 316 a has a width of d1 and secondextension 318 a has a width of d2. In some embodiments, width d2 isgreater than width d1. In some embodiments, width d1 ranges from about1.0 mm to about 4.0 mm. In some embodiments, width d2 ranges from about1.5 mm to about 6.0 mm. A substantially rectangular slot 320 a isprovided between first extension 316 a and second extension 318 a forreceiving first end 502 a of first linkage 500 a therein, as can be seenin FIGS. 1, 2 and 7. First extension 316 a includes a hole 322 a in aninner wall thereof for receiving a pin 600 therein. In some embodiments,hole 322 a does not extend fully through the wall of first extension 316a. Second extension 318 a includes hole 324 a extending therethrough,which is located opposite hole 322 a of first extension 316 a. Amounting pin 600 is inserted into hole 322 a of first extension 316 a,hole 514 a of first linkage 500 a, and hole 324 a of second extension318 a to allow for rotation of the wing 300 a thereabout.

Wing 300 a includes a substantially planar top surface 330 a, as can beseen in FIG. 9C. Wing 300 a includes a substantially rectangular opening332 a adjacent to top surface 330 a. Rectangular opening 332 a isadapted to receive first end 502 a of first linkage 500 a therein in theclosed configuration of the wing 300 a. Proximal end 304 a of wing 300 afurther includes proximal connector portion 326 a having an additionalhole 328 a for operatively connecting wing 300 a to main body 112. Hole328 a is configured to receive a bolt 700 therein.

FIGS. 10A, 10B, and 10C show perspective views of an embodiment ofsecond wing 300 b. Second wing 300 b is substantially identical to firstwing 300 a. Wing 300 b has a distal end 302 b, a proximal end 304 b, afirst lateral side 306 b, and a second lateral side 308 b. In someembodiments, distal end 302 b includes at least one fang adapted forengaging bone and/or tissue. In other embodiments, a bottom surface ofwing 300 b may include a flat roughened surface to achieve gripping ofthe bone and/or tissue.

In some embodiments, distal end 302 b includes first and second fangs310 b, 311 b having a gap 312 b therebetween. In some embodiments, thedimension of the gap 312 b may be about 1.5 mm to about 6 mm. In someembodiments, the gap 312 b may be about 3 mm. In some embodiments, firstfang 310 b has a sharp pointed tip 314 b and second fang 311 b has asharp pointed tip 313 b. First fang 310 b is provided on first lateralside 306 b and is connected to first extension 316 b. Second fang 311 bis provided on second lateral side 308 b and is connected to secondextension 318 b. First extension 316 b has a width of d1 and secondextension 318 b has a width of d2. In some embodiments, width d2 isgreater than width d1. A substantially rectangular slot 320 b isprovided between first extension 316 b and second extension 318 b forreceiving second end 504 b of second linkage 500 b therein, as can beseen in FIG. 2. First extension 316 b includes a hole 322 b in an innerwall thereof for receiving a pin 600 therein. Second extension 318 bincludes hole 324 b extending therethrough, which is located oppositehole 322 b of first extension 316 b. A mounting pin 600 is insertedthrough hole 322 b of first extension 316 b, hole 516 b of secondlinkage 500 b, and hole 324 b of second extension 318 b to allow forrotation of the wing 300 b thereabout, as can be seen in FIG. 2.

Wing 300 b includes a substantially planar top surface 330 b, as can beseen in FIG. 10C. Wing 300 b includes a substantially rectangularopening 332 b adjacent to top surface 330 b. Rectangular opening 332 bis adapted to receive second end 504 b of second linkage 500 b thereinin the closed configuration of the wing 300 b. Proximal end 304 b ofwing 300 b further includes proximal connector portion 326 b having anadditional hole 328 b for operatively connecting wing 300 b to main body112. Hole 328 b is configured to receive a bolt 700 therein.

In some embodiments, in the open position, wings 300 a, 300 b extendcircumferentially a distance of about 2 mm to about 15 mm from the mainbody 112, which may be referred to as the reach, R1, of the wings 300 a,300 b. In some embodiments, the spacing of the gap 312 a between fangs310 a, 311 a may be the same as the spacing of the gap 312 b betweenfangs 310 b, 311 b. In other embodiments, the spacing of the gap 312 abetween fangs 310 a, 311 a may be different from the spacing of the gap312 b between fangs 310 b, 311 b. The fangs 310 a, 311 a, 310 b, 311 bare optimally placed to minimize stress on the spinous process andprevent fracture thereof. The length of any of fangs 310 a, 311 a, 310b, 311 b may be about 0.5 mm to about 5 mm. In some embodiments, eachfang can have a different length as desired.

The design of wings 300 a, 300 b is such that the outer surface acts asa stop relative to main body 112 to control the minimum and maximummovement, thereby preventing closing in on themselves inside the mainbody 112 and also preventing over-deployment. In some embodiments, thewings 300 a, 300 b are extended from the main body 112 at an angle C ofabout 80° to about 90° in the open position. In some embodiments, thewings 300 a, 300 b are extended from the main body 112 at an angle C ofabout 90° in the open position.

FIG. 11 illustrates an embodiment of bolt 700 and FIG. 12 illustrates anembodiment of removable head 718 for connection to bolt 700. Bolt 700includes a shaft 702 having a proximal end 704 and a distal end 706.Proximal end 704 includes a unitary head 708 having a rounded distal end710, a side circumferential edge 712, and a flat bottom surface 714.Distal end 706 includes a reduced diameter cylindrical portion 716.Shaft 702 can be inserted through hole 328 a of wing 300 a, hole 328 bof wing 300 b, and through openings 138 a, 138 b of main body 112.Proximal connector portion 326 a of wing 300 a is thereby adjacent toand connected to proximal connector portion 326 b of wing 300 b by bolt700. Shaft 702 has a diameter configured to fit through holes 328 a, 328b and to allow the wings 300 a, 300 b to freely rotate thereabout. Oncebolt 700 is inserted through main body 112 and wings 300 a, 300 b, aremovable head 718 may be connected to cylindrical portion 716 to holdthe bolt 700 securely in place. The head 718 may be connected by anymechanical fastening means. As shown in FIG. 12, an embodiment ofremovable head 718 is shaped similarly to unitary head 708, having arounded distal end 720, a side circumferential edge 722, and a flatbottom surface 724. Head 718 and head 708 are set within the openings138 a, 138 b such that the distal ends 710, 720 are recessed and do notextend circumferentially beyond the helical threads 120, as seen in FIG.4.

FIG. 13 illustrates an embodiment of nut 200. Nut 200 can be provided onthe proximal end 116 of main body 112. Nut 200 has a proximal side 202,a distal side 204, and an internal bore 206 therethrough. In someembodiments, internal bore 206 has interior helical threads 208 forcooperating with helical threads 120 on the exterior surface of mainbody 112. In operation, the nut 200 can be rotated to move the nutlongitudinally along the shaft of main body 112 such that the distalside 204 engages tissue and/or bone. In some embodiments, proximal side202 has a hexagonal extension 210 with flat sides 212. In someembodiments, distal side 204 forms a grip plate having a plurality offlex arms 214. In one embodiment, the grip plate includes four flex arms214. In other embodiments, the grip plate may include two flex arms,three flex arms, or five or more flex arms.

In some embodiments, each flex arm 214 may have a fixed portion 216 witha smooth top surface 218 and a movable portion 220 with a textured topsurface 222. The movable portion 220 may have a space 226 therebelow.The textured top surface 222 is configured to engage bone or tissue whenthe implant is placed in the body to help anchor the implant 100 inplace. The movable portion 220 is configured to flex into open space 226when the implant 100 is engaged with tissue and/or bone. In someembodiments, the movable portion 220 may flex proximally an amount offrom about 1 degree to about 50 degrees. In some embodiments, themovable portion 220 may flex proximally an amount of from about 1 degreeto about 10 degrees. In some embodiments, the textured top surface 222may include teeth, spikes, or any other type of mechanical grippingsurface. In one embodiment, the textured top surface 222 may includethree substantially triangular shaped teeth 224. In other embodiments,the distal side 204 has a unitary circumferential roughened or texturedsurface without any flex arms. The nut 200 extends circumferentially adistance of about 2 mm to about 15 mm from the main body 112. In someembodiments, the nut 200 extends circumferentially a distance of about 2mm to about 8 mm. This reach allows for sufficient bone fixation whileensuring that the implant 100 can be easily inserted through a standardtissue dilation sleeve/tube.

The present invention may provide a posterior fixation device intendedfor use in the non-cervical spine (T1-S1). The implant is intended forplate fixation/attachment to the spinous process for achieving fusionfor lumbar spinal stenosis, degenerative disc disease,spondylolisthesis, trauma, and/or tumors. The implant may be insertedvia a minimally invasive lateral approach (L1-S1) or a minimallyinvasive posterior approach (T1-S1). In some embodiments, the implantmay be used with bone graft material.

For a spinal implant procedure, a patient may be placed in a proneposition on a frame to decrease the lordosis of the spine and avoidcompression of the abdomen. The surgeon may tilt the pelvis by incliningthe surgical table at the level of the pelvis, allowing for naturaldistraction of the spinous processes. Using a lateral minimally invasivesurgical (MIS) approach, an incision may be made, and a guide wire maybe introduced into the patient's body, which may be done using an aimingdevice under fluoroscopy. The guidewire is then advanced between thespinous processes and pierces the interspinous ligament. Once theguidewire is advanced as desired, which may be approximately 2 cm acrossthe midline of the spine, the aiming device may be removed with theguidewire remaining in place. A guidewire extension may be placed on theproximal end of the guidewire to help maintain guidewire placementduring the procedure. A series of blunt dilators may then be placed overthe guidewire to create a pathway to the spinous processes, which arethen removed with the guidewire remaining in place.

A graduated bone tap may then be inserted over the guidewire. Bone tapmay be used to distract the spinous processes, remove the interspinousligament, and partially decorticate the spinous processes forstimulating bone growth. Bone tap may be rotated clockwise to graduallydecorticate and/or to distract the spinous processes. The bone tap maybe threaded into the interspinous process space such that the threadsare engaged with the spinous processes and tap a path for the implant tobe inserted along. Once adequate distraction is obtained, the degree ofdistraction can be determined by viewing the bone tap's sizing holesunder fluoroscopy. This degree of distraction thereby determines theappropriate implant size, which may be an 8 mm, 10 mm, 12 mm, 14 mm, or16 mm implant. The bone tap and the guidewire can then be removed, andthe spinal implant can be placed. Before the implant is inserted intothe patient, bone graft material is added. Specifically, bone graftmaterial may be added by opening the wings and adding bone graftmaterial into the lumen of the threaded body. Bone graft material mayalso be applied around the exterior threads of the implant.

The implant 100 may be inserted using an inserter device (not shown)into the body of a patient in the closed configuration, as shown inFIGS. 4, 14 and 15. With respect to FIGS. 14 and 15, the plunger 400 isin a proximal position, such that the first and second linkages 500 a,500 b form a first angle A therebetween and the wings 300 a, 300 b arein a closed configuration. Once the implant 100 is inserted into thedesired location in the patient's body, the wings 300 a, 300 b can bemoved to an open configuration, as shown in FIGS. 1, 2, 7 and 8. Theplunger 400 may be moved distally such that the ends 502 a, 504 b of thelinkages 500 a, 500 b, respectively, are caused to separate forming asecond angle B therebetween, shown in FIG. 8. Angle B is greater thanangle A. In some embodiments, angle A is about 35° and angle B is about85°. As the linkages 500 a, 500 b separate, the wings 300 a, 300 brotate around pins 600 and bolt 700 into an open configuration.

The implant may then be moved proximally to engage the wings 300 a, 300b with the bone and/or tissue at the implant site, as can be seen inFIG. 16. The nut 200 may then be moved distally, such as by rotation, toengage the bone and/or tissue as well forming a proximal anchor.Specifically, nut 200 engages a first lateral surface 801 of a firstspinous process 800 and a second lateral surface 804 of a second spinousprocess 802. In some embodiments, the flex arms 214 may be flexedproximally when the nut 200 is tightly engaged with bone and/or tissueat the implant site. Additionally, wings 300 a, 300 b engage a thirdopposite surface 803 of first spinous process 800 and a fourth oppositesurface 806 of second spinous process 802. Specifically, the fangs 310a, 311 a, 310 b, 311 b of wings 300 a, 300 b may engage with the boneand/or tissue at the implant site forming a distal anchor. In someembodiments, the wings 300 a, 300 b and the nut 200 can be engaged onopposite sides of the spinal process when the implant 100 is in place,as seen in FIG. 16.

Second Embodiment

Another embodiment of the invention is shown in FIGS. 17-25, whichillustrates an interspinous process implant 1000. FIG. 17 illustratesimplant 1000 in an open configuration. Implant 1000 may include a mainbody 1012 having a distal end 1014 and a proximal end 1016. Implant 1000further includes a nut 2000 on the proximal end 1016 of main body 1012and extendable first and second wings 3000 a, 3000 b on the distal end1014 of main body 1012. As can be seen in the cross-sectional view ofFIG. 18, implant 1000 further includes a plunger 4000 and first andsecond linkages 5000 a, 5000 b for operatively connecting first andsecond wings 3000 a, 3000 b to main body 1012, as will be describedherein.

As can be seen in FIG. 17, distal end 1014 of main body 1012 includes aconical distal tip 1018 having a rounded distalmost end. In someembodiments, the conical distal tip has a sharp pointed distalmost end.In some embodiments, main body 1012 includes helical threads 120 on anexterior surface thereof. In some embodiments, main body 1012 mayalternatively or additionally include cutting threads or box threads.Helical threads 120 may be provided along the entire exterior surface ofmain body 1012 or along only a portion of the exterior surface of mainbody 1012. In some embodiments, the threads may have a depth of about0.5 to about 3.0 mm, an angle of about 45° to about 100°, and a spacingof about 1.0 mm to about 4.0 mm. In some embodiments, the threads mayhave a depth of about 1.0 mm, an angle of about 60°, and a spacing ofabout 1.75 mm. In some embodiments, distal tip 1018 includes cuttingthreads 1021 to aid in inserting the implant 1000 into the bone (seeFIG. 24C). In some embodiments, distal tip 1018 has a smooth exteriorsurface without any threads thereon. In some embodiments, the distal tip1018 is a solid tip for providing strength during insertion of theimplant 100.

Main body 1012 further includes a proximal portion 1022 extending fromthe proximal end 1016, having hollow bore 1024. The majority of hollowbore 1024 may be substantially cylindrical. Proximal end of hollow bore1024 may have a particular shape such as a hexagonal perimeterconfigured to receive an insertion tool therein (not shown). Proximalend of hollow bore 1024 may also include detents 1025 adapted forreceiving and locking a distal end of an insertion tool therein (notshown).

Main body 1012 also includes a distal portion 1026 extending from thedistal end 1014, having a substantially rectangular window 1028. Thewindow 1028 extends from a first lateral side to a second lateral side,and has a top flat interior wall, and a bottom flat interior wall,similar to main body 112 as shown in FIG. 3. At the distal end of thewindow 1028, top wall and bottom wall include an opening therethroughconfigured to receive a bolt 700 for mounting wings 3000 a, 3000 b, asseen in FIG. 17.

FIG. 23 illustrates implant 1000 with wings 3000 a, 3000 b in a closedconfiguration. Window 1028 of main body 1012 is configured to house adistal portion of the plunger 4000, first and second linkages 5000 a,5000 b, and first and second wings 3000 a, 3000 b when in the closedconfiguration.

FIG. 19 illustrates a second embodiment of plunger 4000. Plunger 4000has a distal end 4002 and proximal end 4004. Proximal end 4004 isconfigured to be located within the bore 1024 of main body 1012 anddistal end 4002 is configured to be located within the window 1028 ofthe main body 112, as seen in FIGS. 18 and 23. Plunger 4000 can be movedlongitudinally within the bore 1024 and window 1028 to open and closethe wings 3000 a, 3000 b, as will be described further below.

With respect to FIG. 19, proximal end 4004 of plunger 4000 has a centralbore 4006 for receiving an inserter device (not shown) therein. In someembodiments, central bore 4006 of plunger 4000 may be threaded tocooperate with threading on an inserter device. Plunger 4000 has asubstantially Y-shaped construction, having a first arm 4008 a and asecond arm 4008 b extending from a solid central portion 4010. First arm4008 a and second arm 4008 b have a space 4009 therebetween. Centralportion 4010 has a substantially cylindrical configuration, as can beseen in FIG. 19. Plunger 4000 does not have indentations like theembodiment of plunger 400 (which can hold bone graft material) becausethe plunger 4000 is located more proximally than plunger 400 when thewings 3000 a, 3000 b are in the open position. Thus, plunger 4000 is notconfigured to extend longitudinally into the window 1028 as far asplunger 400 does. First arm 4008 a and second arm 4008 b each have ahole 4014 a, 4014 b extending therethrough for receiving mounting pin600 therein. In order to connect wings 3000 a, 3000 b to the plunger4000, linkages 5000 a, 5000 b are mounted within the space 4009 betweenthe arms 4008 a, 4008 b. In some embodiments, plunger 4000 may have atotal length of about 9 mm to about 11 mm. In some embodiments, plunger4000 may have a total length of about 10.4 mm. In some embodiments,first and second arms 4008 a, 4008 b may have a length of about 4-5 mm.In some embodiments, first and second arms 4008 a, 4008 b may have alength of about 4.5 mm.

FIG. 20 illustrates an embodiment of first linkage 5000 a. First linkage5000 a has a first end 5002 a and a second end 5004 a. In someembodiments, first linkage 5000 a is substantially oval shaped withfirst end 5002 a having a rounded edge 5006 a, and second end 5004 ahaving a rounded edge 5008 a. First linkage 5000 a further includes astraight bottom edge 5010 a and a curved top edge 5012 a. First end 5002a includes a hole 5014 a extending therethrough and second end 5004 aincludes a hole 5016 a extending therethrough. Holes 5014 a and 5016 aare each configured to receive mounting pin 600 therein. First linkage5000 a includes a substantially planar top surface 5018 a and asubstantially planar bottom surface 5020 a.

Second linkage 5000 b is substantially identical to first linkage 5000a, including a straight bottom edge 5010 b and a curved top edge 5012 b.In some embodiments, first and second linkages 5000 a, 5000 b may have alength of about 12 mm to 14 mm. In some embodiments, first and secondlinkages 5000 a, 5000 b may have a length of about 13.0 mm. In someembodiments, the distance between the holes 5014 a and 5016 a may beabout 9 mm to about 11 mm. The distance between the holes 5014 a and5016 a may be about 9.75 mm. Curved top edges 5012 a, 5012 b may have acurvature with a radius of about 15.0 mm.

FIG. 18 illustrates a cross-sectional view of implant 1000 in an openconfiguration. As can be seen in FIG. 18, second end 5004 a of firstlinkage 5000 a is connected to first end 5002 b of second linkage 5000b. Planar bottom surface 5020 a of first linkage 5000 a is placed incontact with planar top surface 5018 b of second linkage 5000 b. As canbe seen in FIG. 18, a mounting pin 600 is inserted through hole 5016 ain second end 5004 a of first linkage 5000 a, hole 5014 b in first end5002 b of second linkage 5000 b, hole 4014 a in first arm 4008 a ofplunger 4000, and hole 4014 b in second arm 4008 b of plunger 4000 toallow for rotation of the linkages 5000 a, 5000 b thereabout. Theopposite ends of linkages 5000 a, 5000 b are connected to the wings 3000a, 3000 b to allow for rotation thereof, as will be described furtherbelow.

FIGS. 21A, 21B, and 21C show perspective views of an embodiment of firstwing 3000 a. Wing 3000 a has a distal end 3002 a, a proximal end 3004 a,a first lateral side 3006 a, and a second lateral side 3008 a. In someembodiments, distal end 3002 a includes at least one fang extendingtherefrom adapted for engaging bone and/or tissue. In other embodiments,a bottom surface of wing 3000 a may include a flat roughened surface toachieve gripping of the bone and/or tissue.

In some embodiments, distal end 3002 a includes first and second fangs3010 a, 3011 a having a gap 3012 a therebetween. In some embodiments,the dimension of the gap 3012 a may be about 1.5 mm to about 6 mm. Insome embodiments, the gap 3012 a may be about 3 mm. In some embodiments,first fang 3010 a has a sharp pointed tip 3014 a and second fang 3011 ahas a sharp pointed tip 3013 a. First fang 3010 a is provided on firstlateral side 3006 a and is connected to first extension 3016 a. Secondfang 3011 a is provided on second lateral side 3008 a and is connectedto second extension 3018 a. First extension 3016 a has a width of d1 andsecond extension 3018 a has a width of d2. In some embodiments, width d2is greater than width d1. In some embodiments, width d1 ranges fromabout 1.0 mm to about 4.0 mm. In some embodiments, width d1 ranges fromabout 1.0 mm to about 2.2 mm. In some embodiments, width d2 ranges fromabout 1.5 mm to about 6.0 mm. In some embodiments, width d2 ranges fromabout 2.3 mm to about 3.6 mm. A substantially rectangular slot 3020 a isprovided between first extension 3016 a and second extension 3018 a forreceiving first end 5002 a of first linkage 5000 a therein, as can beseen in FIGS. 18 and 22. First extension 3016 a includes a hole 3022 ain an inner wall thereof for receiving pin 600 therein. In someembodiments, hole 3022 a does not extend fully through the wall of firstextension 3016 a. Second extension 3018 a includes hole 3024 a extendingtherethrough, which is located opposite hole 3022 a of first extension3016 a. A mounting pin 600 is inserted into hole 3022 a of firstextension 3016 a, hole 5014 a of first linkage 5000 a, and hole 3024 aof second extension 3018 a to allow for rotation of the wing 3000 athereabout.

Wing 3000 a includes a substantially planar top surface 3030 a and abase surface 3032 a, as can be seen in FIG. 21A. Top surface 3030 aextends at an angle E relative to base surface 3032 a. In someembodiments, angle E is about 35° to about 45°. In some embodiments,angle E is about 41°. Wing 3000 a does not include any opening adjacentto top surface 3030 a, like wing 300 a does. Due to the angled design ofthe wing 3000 a, such an opening is not necessary. Proximal end 3004 aof wing 3000 a further includes proximal connector portion 3026 a havingan additional hole 3028 a for operatively connecting wing 3000 a to mainbody 1012. Hole 3028 a is configured to receive bolt 700 therein.

Second wing 3000 b is substantially identical to first wing 3000 a. Wing3000 b has a distal end 3002 b, a proximal end 3004 b, a first lateralside 3006 b, and a second lateral side 3008 b. In some embodiments,distal end 3002 b includes at least one fang adapted for engaging boneand/or tissue. In other embodiments, a bottom surface of wing 3000 b mayinclude a flat roughened surface to achieve gripping of the bone and/ortissue.

In some embodiments, distal end 3002 b includes first and second fangs3010 b, 3011 b having a gap 3012 b therebetween. In some embodiments,the dimension of the gap 3012 b may be about 1.5 mm to about 6 mm. Insome embodiments, the gap 3012 b may be about 3 mm. In some embodiments,first fang 3010 b has a sharp pointed tip 3014 b and second fang 3011 bhas a sharp pointed tip 3013 b. First fang 3010 b is provided on firstlateral side 3006 b and is connected to first extension 3016 b. Secondfang 3011 b is provided on second lateral side 3008 b and is connectedto second extension 3018 b. First extension 3016 b has a width of d1 andsecond extension 3018 b has a width of d2. In some embodiments, width d2is greater than width d1. A substantially rectangular slot 3020 b isprovided between first extension 3016 b and second extension 3018 b forreceiving second end 5004 b of second linkage 5000 b therein, as can beseen in FIG. 22. First extension 3016 b includes a hole in an inner wallthereof for receiving a pin 600 therein. Second extension 3018 bincludes hole 3024 b extending therethrough, which is located oppositethe hole of first extension 3016 b. A mounting pin 600 is insertedthrough hole of first extension 3016 b, hole 5016 b of second linkage5000 b, and hole 3024 b of second extension 3018 b to allow for rotationof the wing 3000 b thereabout, as can be seen in FIG. 22. FIG. 22illustrates the wings 3000 a, 3000 b, first and second linkages 5000 a,5000 b, and plunger 4000, but does not show main body 1012 in order tobetter view the internal linkages.

Wing 3000 b includes a substantially planar top surface, similar to wing3000 a, as seen in FIG. 21A. Proximal end 3004 b of wing 3000 b furtherincludes proximal connector portion 3026 b having an additional hole3028 b for operatively connecting wing 3000 b to main body 1012. Hole3028 b is configured to receive a bolt 700 therein, as seen in FIG. 22.

In some embodiments, in the open position, wings 3000 a, 3000 b extendcircumferentially a distance of about 2 mm to about 15 mm from the mainbody 1012, which may be referred to as the reach, R₂, of the wings 3000a, 3000 b. In some embodiments, the spacing of the gap 3012 a betweenfangs 3010 a, 3011 a may be the same as the spacing of the gap 3012 bbetween fangs 3010 b, 3011 b. In other embodiments, the spacing of thegap 3012 a between fangs 3010 a, 3011 a may be different from thespacing of the gap 3012 b between fangs 3010 b, 3011 b. The fangs 3010a, 3011 a, 3010 b, 3011 b are optimally placed to minimize stress on thespinous process and prevent fracture thereof. The length of any of fangs3010 a, 3011 a, 3010 b, 3011 b may be about 0.5 mm to about 5 mm. Insome embodiments, each fang can have a different length as desired.

As seen in FIGS. 17-18, the design of wings 3000 a, 3000 b is such thatthe base surface 3032 a, 3032 b acts as a stop relative to main body1012 to control the minimum and maximum movement, thereby preventingclosing in on themselves inside the main body 1012 and also preventingover-deployment. In some embodiments, the wings 3000 a, 3000 b areextended from the main body 1012 at an angle D of about 50° to about 70°in the open position. In some embodiments, the wings 3000 a, 3000 b areextended from the main body 1012 at an angle D of about 60° in the openposition.

FIGS. 24A, 24B, 24C illustrate an embodiment of nut 2000. Nut 2000 canbe provided on the proximal end 1016 of main body 1012. Nut 2000 has aproximal side 2002, a distal side 2004, and an internal bore 2006therethrough. In some embodiments, internal bore 2006 has interiorhelical threads 2008 for cooperating with helical threads 120 on theexterior surface of main body 1012. In operation, the nut 2000 can berotated to move the nut longitudinally along the shaft of main body 1012such that the distal side 2004 engages tissue and/or bone. In someembodiments, proximal side 2002 has a hexagonal extension 2010 with flatsides 2012.

In some embodiments, distal side 2004 forms a grip plate having atextured surface 2030. Textured surface 2030 may be configured to engagebone or tissue when the implant 1000 is placed in the body to helpanchor the implant 1000 in place, as seen in FIG. 25. In someembodiments, the textured surface 2030 may include bumps, crenelations,teeth, spikes, or any other type of mechanical gripping surface. The nut2000 extends circumferentially a distance of about 2 mm to about 15 mmfrom the main body 1012. In some embodiments, the nut 2000 extendscircumferentially a distance of about 2 mm to about 8 mm. This reachallows for sufficient bone fixation while ensuring that the implant 1000can be easily inserted through a standard tissue dilation sleeve/tube.In some embodiments, nut 2000 can be provided in two sizes—a first sizefor implants of 8 mm, 10 mm, and 12 mm; and a second size for implantsof 14 mm and 16 mm.

The implant 1000 may be inserted using an inserter device (not shown)into the body of a patient in the closed configuration, as shown in FIG.23. With respect to FIG. 23, the plunger 4000 is in a proximal position,such that the first and second linkages 5000 a, 5000 b form a firstangle F therebetween and the wings 3000 a, 3000 b are in a closedconfiguration. Once the implant 1000 is inserted into the desiredlocation in the patient's body, the wings 3000 a, 3000 b can be moved toan open configuration, as shown in FIGS. 17, 18 and 22. The plunger 4000may be moved distally such that the ends 5002 a, 5004 b of the linkages5000 a, 5000 b, respectively, are caused to separate forming a secondangle G therebetween, shown in FIGS. 18 and 22. Angle G is greater thanangle F. In some embodiments, angle F is about 25° and angle G is about45°. As the linkages 5000 a, 5000 b separate, the wings 3000 a, 3000 brotate around pins 600 and bolt 700 into an open configuration.

The implant may then be moved proximally to engage the wings 3000 a,3000 b with the bone and/or tissue at the implant site, as can be seenin FIG. 25. The nut 2000 may then be moved distally, such as byrotation, to engage the bone and/or tissue as well forming a proximalanchor. Specifically, nut 2000 engages a first lateral surface 801 of afirst spinous process 800 and a second lateral surface 804 of a secondspinous process 802. Additionally, wings 3000 a, 3000 b engage a thirdopposite surface 803 of first spinous process 800 and a fourth oppositesurface 806 of second spinous process 802. Specifically, the fangs 3010a, 3011 a, 3010 b, 3011 b of wings 3000 a, 3000 b may engage with thebone and/or tissue at the implant site forming a distal anchor. In someembodiments, the wings 3000 a, 3000 b and the nut 2000 can be engaged onopposite sides of the spinal process when the implant 1000 is in place,as seen in FIG. 25.

The implant 100, 1000 may be provided in different selected sizes toproperly fit into the desired space of a particular patient. The implantbody diameter may provide for a range of about 6-20 mm spinous processspace distraction. In some embodiments, the diameter of the main body112, 1012 may be about 8 mm, about 10 mm, about 12 mm, about 14 mm, orabout 16 mm. The sizes of the implant may be color-coded to allow thesurgeon to easily identify the size of the implant and match the implantwith a properly sized insertion tool (not shown), which may have similarsize color-coding.

In some embodiments, all or part of the implant may be composed oftitanium or a titanium alloy. In other embodiments, all or part of theimplant may be composed of stainless steel. In some embodiments, all orpart of the implant may be composed of a polymer or a bioabsorbablematerial. In some embodiments, the implant may be manufactured by anadditive manufacturing process. In some embodiments, the implant may bemanufactured by machining or molding. In some embodiments, all or partof the implant may include a coating on at least one surface thereof. Insome embodiments, at least one outer surface of the implant may becoated with hydroxyapatite (HA). In some embodiments, multiple surfacesmay be coated with HA.

In some embodiments, the implant 100, 1000 may have a total length ofabout 30 mm to 45 mm. In some embodiments, the implant 100, 1000 mayhave a total length of about 32 mm to about 34 mm. In some embodiments,the implant 100 may have a total length of about 33 mm. In someembodiments, the implant 1000 may have a total length of about 34 mm.

In some embodiments, main body 112, 1012 may be adapted to contain bonegraft material therein. The bone graft material may be added to theimplant 100, 1000 by holding wing 300 a, 3000 a open and holding wing300 b, 3000 b closed and injecting bone graft material into the mainbody 112, 1012 (or vice versa). Bone graft material may also be appliedaround the exterior helical threads 120 before insertion of the implant100, 1000 into the body. In some embodiments, the bone graft materialmay be viscous to avoid any interference with the proper functioning ofthe wings 300 a, 3000 a, 300 b, 3000 b. The volume of the bone graftmaterial may range from about 0.5 cc to about 3.0 cc, or from about 1.2cc to about 2.5 cc, depending on the size of the implant 100.

Features described above as well as those claimed below may be combinedin various ways without departing from the scope hereof. The followingexamples illustrate some possible, non-limiting combinations:

(A1) A spinal implant comprising: a main body having a central bore anda longitudinal axis extending between a proximal end and a distal end; aproximal anchor including a nut received on an outer surface of the mainbody; a distal anchor having a first closed configuration and a secondopen configuration, the distal anchor including: a first wing having afirst inner end and a first outer end, and a second wing having a secondinner end and a second outer end, wherein the first inner end isrotatably connected to the second inner end at a first pivot point; andan internal plunger having a proximal end and a distal end, the internalplunger housed within the central bore of the main body, the distal endof the internal plunger connected to both a proximal end of a firstlinkage and a proximal end of a second linkage at a second pivot point,wherein longitudinal distal movement of the internal plunger rotates thefirst outer end of the first wing and the second outer end of the secondwing distally to transition from the first closed configuration to thesecond open configuration, and longitudinal proximal movement of theinternal plunger folds the first wing and the second wing proximally totransition from the second open configuration to the first closedconfiguration.

(A2) For the spinal implant denoted as (A1), wherein a distal end of thefirst linkage is connected to the first wing at a third pivot point nearthe first inner end, and a distal end of the second linkage is connectedto the second wing at a fourth pivot point near the second inner end.

(A3) For the spinal implant denoted as (A1) or (A2), wherein the firstwing and the second wing form an angle of about 60 degrees with respectto the main body in the second open configuration.

(A4) For the spinal implant denoted as any of (A1) or (A2), wherein thefirst wing and the second wing form an angle of about 80 degrees toabout 90 degrees with respect to the main body in the second openconfiguration.

(A5) For the spinal implant denoted as any of (A1) through (A4), whereinthe distal end of the internal plunger includes: a first arm, a secondarm, and a space between the first arm and the second arm, wherein aproximal end of the first linkage and a proximal end of the secondlinkage are mounted in the space between the first arm and the secondarm of the internal plunger.

(A6) For the spinal implant denoted as any of (A1) through (A5), whereinthe first linkage and the second linkage are substantially identical.

(A7) For the spinal implant denoted as any of (A1) through (A6), whereinthe first wing includes a substantially planar top surface and a basesurface at the first inner end, the top surface extending at an angle ofabout 35 to about 45 degrees relative to the base surface.

(A8) For the spinal implant denoted as any of (A1) through (A7), whereinthe second wing includes a substantially planar top surface and a basesurface at the second inner end, the top surface extending at an angleof about 35 to about 45 degrees relative to the base surface.

(A9) For the spinal implant denoted as any of (A1) through (A8), whereinthe first linkage and the second linkage form an angle of about 45degrees in the second open configuration.

(A10) For the spinal implant denoted as any of (A1) through (A9),wherein the first linkage and the second linkage form an angle of about25 degrees in the first closed configuration.

(A11) For the spinal implant denoted as any of (A1) through (A8),wherein the first linkage and the second linkage form an angle of about85 degrees in the second open configuration.

(A12) For the spinal implant denoted as any of (A1) through (A11),wherein the first wing includes a first slot on an inner surface forreceiving the first linkage therein, and the second wing includes asecond slot on an inner surface for receiving the second linkagetherein.

(A13) For the spinal implant denoted as any of (A1) through (A12),wherein at least one of the first outer end of the first wing includesat least one pointed protrusion adapted to engage tissue or bone or thesecond outer end of the second wing includes at least one pointedprotrusion adapted to engage tissue or bone.

(A14) For the spinal implant denoted as any of (A1) through (A13),wherein a distal side of the nut includes a textured surface adapted toengage tissue or bone.

(B1) A method of placing a spinal implant at a treatment sitecomprising: providing a spinal implant in a first closed configuration,the spinal implant including: a main body having a central bore and alongitudinal axis extending between a proximal end and a distal end; aproximal anchor including a nut received on an outer surface of the mainbody; a distal anchor including: a first wing having a first inner endand a first outer end, and a second wing having a second inner end and asecond outer end, wherein the first inner end is rotatably connected tothe second inner end at a first pivot point; and an internal plungerhaving a proximal end and a distal end, the internal plunger housedwithin the central bore of the main body, the distal end of the internalplunger connected to both a proximal end of a first linkage and aproximal end of a second linkage at a second pivot point, placing thespinal implant in a patient at a desired treatment site; and sliding theinternal plunger distally along the longitudinal axis to rotate thefirst outer end of the first wing and the second outer end of the secondwing distally to a second open configuration.

(B2) For the method denoted as (B1), further comprising: sliding theinternal plunger proximally along the longitudinal axis to fold thefirst wing and the second wing proximally towards the first closedconfiguration to engage the first wing and the second wing with bone ortissue at the treatment site.

(B3) For the method denoted as (B1) or (B2), further comprising: movingthe nut distally along the main body to engage a distal side of the nutwith tissue or bone.

(B4) For the method denoted as any of (B1) through (B3), furthercomprising: sliding the internal plunger proximally along thelongitudinal axis to move the first wing and the second wing to thefirst closed configuration to withdraw the spinal implant from thepatient.

(C1) A spinal implant comprising: a main body having a central bore anda longitudinal axis extending between a proximal end and a distal end; aproximal anchor including a nut having a textured distal surface, thenut received around an outer surface of the main body; a distal anchorhaving a first closed configuration and a second open configuration, thedistal anchor including: a first wing having a first inner end, a firstouter end, a first substantially planar top surface, and a first basesurface at the first inner end, the first top surface extending at anangle of about 35 to about 45 degrees relative to the first basesurface, and a second wing having a second inner end, a second outerend, a second substantially planar top surface, and a second basesurface, the second top surface extending at an angle of about 35 toabout 45 degrees relative to the second base surface, wherein the firstinner end is rotatably connected to the second inner end at a firstpivot point; and an internal plunger having a proximal end and a distalend, the internal plunger housed within the central bore of the mainbody, the distal end of the internal plunger connected to both aproximal end of a first linkage and a proximal end of a second linkageat a second pivot point, wherein longitudinal distal movement of theinternal plunger rotates the first outer end of the first wing and thesecond outer end of the second wing distally to transition from thefirst closed configuration to the second open configuration, andlongitudinal proximal movement of the internal plunger folds the firstwing and the second wing proximally to transition from the second openconfiguration to the first closed configuration.

(C2) For the spinal implant denoted as (C1), wherein the first wing andthe second wing form an angle of about 60 degrees with respect to themain body in the second open configuration.

Although the invention has been described with reference to theembodiments illustrated in the attached drawing figures, it is notedthat equivalents may be employed and substitutions made herein withoutdeparting from the scope of the invention as recited in the claims.

Having thus described various embodiments of the invention, what isclaimed as new and desired to be protected by Letters Patent includesthe following:
 1. A spinal implant comprising: a main body having acentral bore and a longitudinal axis extending between a proximal endand a distal end; a proximal anchor comprising a nut received on anouter surface of the main body; a distal anchor having a first closedconfiguration and a second open configuration, said distal anchorcomprising: a first wing having a first inner end and a first outer end,and a second wing having a second inner end and a second outer end,wherein said first inner end is rotatably connected to said second innerend at a first pivot point; and an internal plunger having a proximalend and a distal end, said internal plunger housed within the centralbore of the main body, said distal end of the internal plunger connectedto both a proximal end of a first linkage and a proximal end of a secondlinkage at a second pivot point, wherein longitudinal distal movement ofthe internal plunger rotates the first outer end of the first wing andthe second outer end of the second wing distally to transition from thefirst closed configuration to the second open configuration, andlongitudinal proximal movement of the internal plunger folds the firstwing and the second wing proximally to transition from the second openconfiguration to the first closed configuration.
 2. The spinal implantof claim 1, wherein a distal end of said first linkage is connected tothe first wing at a third pivot point near the first inner end, and adistal end of said second linkage is connected to the second wing at afourth pivot point near the second inner end.
 3. The spinal implant ofclaim 1, wherein the first wing and the second wing form an angle ofabout 60 degrees with respect to the main body in the second openconfiguration.
 4. The spinal implant of claim 1, wherein the first wingand the second wing form an angle of about 80 degrees to about 90degrees with respect to the main body in the second open configuration.5. The spinal implant of claim 1, wherein the distal end of the internalplunger comprises: a first arm, a second arm, and a space between thefirst arm and the second arm, wherein a proximal end of the firstlinkage and a proximal end of the second linkage are mounted in thespace between the first arm and the second arm of the internal plunger.6. The spinal implant of claim 1, wherein the first linkage and thesecond linkage are substantially identical.
 7. The spinal implant ofclaim 1, wherein the first wing comprises a substantially planar topsurface and a base surface at the first inner end, the top surfaceextending at an angle of about 35 to about 45 degrees relative to thebase surface.
 8. The spinal implant of claim 7, wherein the second wingcomprises a substantially planar top surface and a base surface at thesecond inner end, the top surface extending at an angle of about 35 toabout 45 degrees relative to the base surface.
 9. The spinal implant ofclaim 1, wherein the first linkage and the second linkage form an angleof about 45 degrees in the second open configuration.
 10. The spinalimplant of claim 1, wherein the first linkage and the second linkageform an angle of about 25 degrees in the first closed configuration. 11.The spinal implant of claim 1, wherein the first linkage and the secondlinkage form an angle of about 85 degrees in the second openconfiguration.
 12. The spinal implant of claim 2, wherein the first wingincludes a first slot on an inner surface for receiving the firstlinkage therein, and the second wing includes a second slot on an innersurface for receiving the second linkage therein.
 13. The spinal implantof claim 1, wherein at least one of the first outer end of the firstwing includes at least one pointed protrusion adapted to engage tissueor bone or the second outer end of the second wing includes at least onepointed protrusion adapted to engage tissue or bone.
 14. The spinalimplant of claim 1, wherein a distal side of the nut comprises atextured surface adapted to engage tissue or bone.
 15. A method ofplacing a spinal implant at a treatment site comprising: providing aspinal implant in a first closed configuration, said spinal implantcomprising: a main body having a central bore and a longitudinal axisextending between a proximal end and a distal end; a proximal anchorcomprising a nut received on an outer surface of the main body; a distalanchor comprising: a first wing having a first inner end and a firstouter end, and a second wing having a second inner end and a secondouter end, wherein said first inner end is rotatably connected to saidsecond inner end at a first pivot point; and an internal plunger havinga proximal end and a distal end, said internal plunger housed within thecentral bore of the main body, said distal end of the internal plungerconnected to both a proximal end of a first linkage and a proximal endof a second linkage at a second pivot point, placing the spinal implantin a patient at a desired treatment site; and sliding the internalplunger distally along the longitudinal axis to rotate the first outerend of the first wing and the second outer end of the second wingdistally to a second open configuration.
 16. The method of claim 15,further comprising: sliding the internal plunger proximally along thelongitudinal axis to fold the first wing and the second wing proximallytowards the first closed configuration to engage the first wing and thesecond wing with bone or tissue at the treatment site.
 17. The method ofclaim 16, further comprising: moving the nut distally along the mainbody to engage a distal side of the nut with tissue or bone.
 18. Themethod of claim 17, further comprising: sliding the internal plungerproximally along the longitudinal axis to move the first wing and thesecond wing to the first closed configuration to withdraw the spinalimplant from the patient.
 19. A spinal implant comprising: a main bodyhaving a central bore and a longitudinal axis extending between aproximal end and a distal end; a proximal anchor comprising a nut havinga textured distal surface, said nut received around an outer surface ofthe main body; a distal anchor having a first closed configuration and asecond open configuration, said distal anchor comprising: a first winghaving a first inner end, a first outer end, a first substantiallyplanar top surface, and a first base surface at the first inner end, thefirst top surface extending at an angle of about 35 to about 45 degreesrelative to the first base surface, and a second wing having a secondinner end, a second outer end, a second substantially planar topsurface, and a second base surface, the second top surface extending atan angle of about 35 to about 45 degrees relative to the second basesurface, wherein said first inner end is rotatably connected to saidsecond inner end at a first pivot point; and an internal plunger havinga proximal end and a distal end, said internal plunger housed within thecentral bore of the main body, said distal end of the internal plungerconnected to both a proximal end of a first linkage and a proximal endof a second linkage at a second pivot point, wherein longitudinal distalmovement of the internal plunger rotates the first outer end of thefirst wing and the second outer end of the second wing distally totransition from the first closed configuration to the second openconfiguration, and longitudinal proximal movement of the internalplunger folds the first wing and the second wing proximally totransition from the second open configuration to the first closedconfiguration.
 20. The spinal implant of claim 19, wherein the firstwing and the second wing form an angle of about 60 degrees with respectto the main body in the second open configuration.